Frappe State Machine Helper
Generate state machine logic for managing complex document states and transitions in Frappe DocTypes.
When to Use This Skill
Claude should invoke this skill when:
- •User wants to implement document status management
- •User needs state transition logic
- •User mentions state machine, status workflow, or document lifecycle
- •User wants to validate state transitions
- •User needs state-dependent behavior
Capabilities
1. State Transition Logic
Order Status State Machine:
python
class SalesOrder(Document):
def validate(self):
self.validate_state_transition()
def validate_state_transition(self):
"""Validate allowed state transitions"""
if not self.is_new():
old_status = frappe.db.get_value('Sales Order', self.name, 'status')
# Define allowed transitions
allowed_transitions = {
'Draft': ['Pending', 'Cancelled'],
'Pending': ['Confirmed', 'Cancelled'],
'Confirmed': ['In Progress', 'Cancelled'],
'In Progress': ['Completed', 'On Hold'],
'On Hold': ['In Progress', 'Cancelled'],
'Completed': [], # Terminal state
'Cancelled': [] # Terminal state
}
if old_status != self.status:
allowed = allowed_transitions.get(old_status, [])
if self.status not in allowed:
frappe.throw(
_(f'Cannot transition from {old_status} to {self.status}')
)
def on_submit(self):
self.status = 'Confirmed'
def on_cancel(self):
self.status = 'Cancelled'
2. State-Dependent Actions
Actions Based on State:
python
class PaymentEntry(Document):
def validate(self):
if self.status == 'Draft':
self.validate_draft_entry()
elif self.status == 'Submitted':
self.validate_submitted_entry()
def before_submit(self):
# Actions before state change
if self.payment_type == 'Pay':
self.validate_sufficient_balance()
self.status = 'Submitted'
def on_cancel(self):
# Reverse actions
if self.status == 'Submitted':
self.reverse_gl_entries()
self.status = 'Cancelled'
References
State Management Examples: